Does it work? = Does it operate as it's supposed to?
Is it working? = Is it operating as it's supposed to now?
Examples: Before buying an old microwave at a garage sale, Jim asked, "Does it work?"
The office printer was out of toner this morning. This afternoon Tom wants to print something.
He thinks that the toner was replaced, but he is not sure. He asks a colleague:
"Is the printer working?"
P.S. Welcome to the Forum, Mhndlsz!